FERN, a name often used to denote the whole botanical class of Pteridophyta, including both the true ferns, Filicales, by far the largest group of this class in the existing flora, and the fern like plants, Equisetales, Lycopodiales, etc. (see PTERIDOPHYTA). FERNALD, MERRITT LYNDON ), Ameri can botanist, was born at Orono, Me., on Oct. 5, 1873, and gradu ated at Harvard university in 1897. From 1895 to 1902 he served as assistant at the Gray herbarium, Harvard. He then became instructor and, in 1905, assistant professor, of botany. In 1915 he was made Fisher professor of natural history. Thirty seasons of active field exploration in New England, the Mari time Provinces, Quebec, Newfoundland and Labrador, made him an authority on the distribution and relationships of the flora of northeastern America, concerning which he wrote numerous botanical papers and monographs. In 1925 he published Per sistence of Plants in Unglaciated Areas of Boreal America, a critical study demonstrating that the numerous arctic-alpine spe cies found in unglaciated parts of the Gaspe peninsula, Magdalen islands, the Long range of Newfoundland and the Torngat moun tains of Labrador, but elsewhere occurring no nearer than the Cordilleran areas of western America and the Arctic archipelago, are survivals of the pre-glacial flora of boreal America. With B. L. Robinson he was the co-editor of the 7th edition of Gray's New Manual of Botany (1908) .